Neural Control and Coordination — Page 6 | NEET Biology

Q51

During the propagation of a nerve impulse, the action potential results from the movement of:

A

K^{+}

ions from extracellular fluid to intracellular fluid

B

Na^{+}

ions from intracellular fluid to extracellular fluid

C

K^{+}

ions from intracellular fluid to extracellular fluid

D

Na^{+}

ions from extracellular fluid to intracellular fluid

Correct Answer

Option D

Solution

(d) During propagation of nerve impulse, $Na^{+}$ enters inside so positive charge is formed inside the membrane. $K^{+}$ ions come out.

Q52

Which part of human brain is concerned with the regulation of body temperature?

A Cerebellum

B Cerebrum

C Hypothalamus

D Medulla Oblongata

Correct Answer

Option C

Solution

(c) Hypothalamus part of human brain is concerned with the regulation of body temperature.

Q53

The nerve centres which control the body temperature and the urge for eating are contained in:

A hypothalamus

B pons

C cerebellum

D thalamus

Correct Answer

Option A

Solution

(a) Hypothalamus contains important nerve centres that controls the body temperature, thirst, hunger and eating, water balance and sexual function.

Q54

When a neuron is in resting state i.e., not conducting any impulse, the axonal membrane is:

A comparatively more permeable to

Na^{+}

ions and nearly impermeable to

K^{+}

ions

B equally permeable to both

Na^{+}

and

K^{+}

ions

C impermeable to both

Na^{+}

and

K^{+}

ions

D comparatively more permeable to

K^{+}

ions and nearly impermeable to

Na^{+}

ions

Correct Answer

Option D

Solution

(d) When a neuron is in resting state i.e., not conducting any impulse, the axonal membrane is comparatively more permeable to K+ ion and nearly impermeable to Na+ ions.

Q55

A person entering an empty room suddenly finds a snake right in front on opening the door. Which one of the following is likely to happen in his neuro-hormonal control system?

A Sympathetic nervous system is activated releasing epinephrin and norepinephrin from adrenal medulla.

B Neurotransmitters diffuse rapidly across the cleft and transmit a nerve impulse.

C Hypothalamus activates the parasympathetic division of brain.

D Sympathetic nervous system is activated releasing epinephrin and norepinephrin from adrenal cortex.

Correct Answer

Option A

Solution

(a) Epinephrine and norepinephrine are secreted by adrenal medulla in response to stress of any kind and during emergency situations and are called emergency hormones or hormones of flight, or fight.

Q56

The human hind brain comprises three parts, one of which is :

A Spinal cord

B Corpus callosum

C Cerebellum

D Hypothalamus

Correct Answer

Option C

Solution

(c) The human hind brain comprises of pons, cerebellum and medulla oblongata.

Q57

Which of the following structures or regions is incorrectly paired with its functions?

A Medulla oblongata : controls respiration and cardiovascular reflexes.

B Limbic system : consists of fibre tracts that interconnect different regions of brain; controls movement.

C Corpus callosum : band of fibers connecting left and right cerebral hemispheres.

D Hypothalamus : production of releasing hormones and regulation of temperature, hunger and thirst.

Correct Answer

Option B

Solution

(b) The limbic system (emotional motor system) is responsible for the experience and expression of emotion but not movement.